C175-16 Locomotive Engine Caterpillar

Use this procedure to troubleshoot a high fuel temperature. Also, use this procedure if one of the following event codes is active or logged.

Table 1

J1939 Code and Description	CDL Code and Description	Comments
174-0 Engine Fuel Temperature 1 : High - most severe (3)	E363 (3) High Fuel Supply Temperature	The fuel temperature sensor on the secondary filter head is higher than expected.
174-15 Engine Fuel Temperature 1 : High - least severe (1)	E363 (1) High Fuel Supply Temperature	The fuel temperature sensor on the secondary filter head is higher than expected.
174-16 Engine Fuel Temperature 1 : High - moderate severity (2)	E363 (2) High Fuel Supply Temperature	The fuel temperature sensor on the secondary filter head is higher than expected.
3468-0 Engine Fuel Temperature 2 : High - most severe (3)	E770 (3) High Fuel Rail Temperature	The fuel temperature sensor on the high-pressure fuel pump is higher than expected.
3468-15 Engine Fuel Temperature 2 : High - least severe (1)	E770 (1) High Fuel Rail Temperature	The fuel temperature sensor on the high-pressure fuel pump is higher than expected.
3468-16 Engine Fuel Temperature 2 : High - moderate severity (2)	E770 (2) High Fuel Rail Temperature	The fuel temperature sensor on the high-pressure fuel pump is higher than expected.

Table 2

Associated Codes
J1939 Code	CDL Code	Troubleshooting Procedure
174-3	174-3	Troubleshooting, "Sensor Signal (Analog, Passive) - Test"
174-4	174-4	Troubleshooting, "Sensor Signal (Analog, Passive) - Test"
1077-11	1684-11	Troubleshooting, "Fuel Injection Pump Circuit - Test"
1077-12	1684-12	Troubleshooting, "Fuel Injection Pump Circuit - Test"
3468-3	2323-3	Troubleshooting, "Sensor Signal (Analog, Passive) - Test"
3468-4	2323-4	Troubleshooting, "Sensor Signal (Analog, Passive) - Test"

If high fuel temperature shuts down the engine, cycle the power to the engine Electronic Control Module (ECM) to restart.

Probable Causes

• Codes

• Fuel level

• Fuel cooler

• Sensor

Recommended Actions

Table 3

Troubleshooting Test Step	Value	Result
1. Check for Codes A. Connect Cat ® Electronic Technician (ET) to the service tool connector. B. Look for active codes that are associated with the system for the event code.	Codes	Result: An associated code is active. Repair: Troubleshoot any associated codes before continuing with this test. Result: An E363 or 174 code is active or logged. Proceed to Test Step 2. Result: An E770 or 3468 code is active or logged. Proceed to Test Step 5.
2. Check the Fuel Tank Level A. Turn the keyswitch to the OFF position. B. Visually inspect the fuel level to make sure that the tank level is not too low.	Fuel Level	Result: The fuel level is not low. Proceed to Test Step 3. Result: The fuel level is low. Proceed to Test Step 6.
3. Check the Fuel Cooler for a Restriction A. Turn the keyswitch to the OFF position. B. Visually inspect the fuel cooler to see if there are any blockages or obstructions.	Restrictions	Result: There was not debris or restrictions in the fuel cooler. Proceed to Test Step 4. Result: There was debris or restrictions in the fuel cooler. Repair: Clean or replace the fuel cooler. Proceed to Test Step 6.
4. Replace the Fuel Temperature Sensor on the Secondary Filter Head A. Turn the keyswitch to the OFF position. B. Replace the fuel temperature sensor on the secondary filter head.	Sensor	Result: The fuel temperature sensor on the secondary filter head was replaced. Proceed to Test Step 6.
5. Replace the Fuel Rail Temperature Sensor A. Connect Cat ET. B. Release the pressure in the high-pressure rail by loosening the end plug on one of the last two fuel accumulators. Refer to Testing and Adjusting, "Fuel Rail Pressure - Release" for instructions on how to release the pressurized fuel. C. Use Cat ET to monitor the following pressure: - "Fuel Rail Pressure" Note: The "Fuel Rail Pressure" should read 0 ± 8 MPa (0 ± 1160 psi). D. Replace the fuel rail temperature sensor.	Sensor	Result: The fuel rail temperature sensor was replaced. Proceed to Test Step 6.
6. Check for Codes A. Start the engine. B. Run the engine to run until normal operating temperature is reached. C. Connect Cat ET. D. Use Cat ET to monitor the following: - Codes	Codes	Result: A code is not active. Return to service. Result: An E770 or 3468 code is active. Repair: A failed high-pressure fuel pump has been detected. 1. Release the pressure in the high-pressure rail by loosening the end plug on one of the last two fuel accumulators. Refer to Testing and Adjusting, "Fuel Rail Pressure - Release" for instructions on how to release the pressurized fuel. 2. Use Cat ET to monitor the following pressure: - "Fuel Rail Pressure" Note: The "Fuel Rail Pressure" should read 0 ± 8 MPa (0 ± 1160 psi). 3. Replace the high-pressure fuel pump. Verify that the repair eliminated the problem.

If the procedure did not correct the issue, contact your Cat dealer Technical Communicator (TC). For further assistance, your TC can confer with the Dealer Solutions Network (DSN).